<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=600, initial-scale=1.0">
    <title>Document</title>
    <style>
        #lstCourse :last-child {
            color: red;
        }
    </style>
</head>
<body>
    <ul id="lstCourse">
        <li class="course">Java</li>
        <li class="course">Python</li>
        <li class="course">JavaScript</li>
        <li class="course">C</li>
    </ul>
    <script>
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        console.log(oList.nodeName)   // UL
        console.log(oList.innerHTML)
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        console.log(oElements.length)
        const oLis = document.getElementsByClassName('course')
        console.log(oLis.length)
        
        const oLastLi = document.querySelector('#lstCourse :last-child')
        console.log(oLastLi.innerHTML)

        const oAllLi = document.querySelectorAll('.course')
        console.log(oAllLi.length)
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</body>
</html>